Unable to download updates - Connection to FTP server fails

I have been trying to dowload the latest updates to upgrade from 10.5 to 12.5. The only thing that successfully downloads is the CMC but after that this is the error i get no matter what. The download starts and consistently fails after a few minutes. I choose Test FTP connection and then it says "Connectivity to the FTP server has been successfully established" but then the update will fail again. Very frustrating as the manual download seems to only give me the CMC but no patches. Any ideas?